Detector devices by means of which gases can be simply, rapidly and inexpensively investigated with respect to the constituents contained therein are known in various forms.
United Kingdom Pat. 2,155,178 discloses a measuring device which operates with an indicator tape containing a reagent. The gas to be tested is drawn through this indicator tape by means of suction. The reagent on the indicator tape react specifically with the constituents of the sample which are to be determined. This leads to a change in coloration which can be photoelectrically detected.
The detector devices are often configured as gas detector tubes. The reagents are arranged in the detector tube so that they have the most intensive contact possible with the gas to be detected when the latter is drawn through the tube by means of suction such as with a special pump.
With the development of detector devices of this kind, the problem is often encountered that several reagents must be utilized which can not be stored together. For this reason, the reagents in the detector devices referred to above are separated into component quantities with each component quantity containing only such reagents which are capable of being stored in contact with each other. This condition of the detector device is characterized as being the storage condition.
Such detector devices are transferred into the use condition only shortly before the use thereof with the previously separated component quantities of the reagents being brought into contact with each other.
In the indicator tape referred to in United Kingdom Pat. No. 2,155,178, three different microcapsules are, for example, provided which contain the component quantities of the reagents and which are destroyed by means of corresponding squeeze rollers of the particular device so that the reagent solutions contained therein flow together and become mixed.
German Pat. No. 713,659 and German Utility Model Registration DE-GM 1,748,816 disclose two different constructions of detector tubes which contain two component chambers separated from each other in the storage condition for two component quantities of reagents which are not capable of common storage. In the detector tube of German Pat. No. 713,659, the connection between the component chambers and therewith the mixing of the reagents contained therein is made possible in that the separation wall contains a plastic plug which is sucked out by the partial vacuum developed when the gas to be tested is drawn in by suction. In DE-GM 1,748,816, the separation is achieved by means of a separation film which is torn by the suction action of the pump. Detector tubes are also known wherein the reagents are contained in separate ampules which must be broken to achieve a transfer into the use condition.
The known detector devices can not be satisfactory in all respects. Especially, they are often complex to produce and/or are not adequately reliable in use.